The airplane departed Kadena AFB on a night patrol flight over the Pacific Ocean. While cruising at low height in a flat attitude some 320 km east of Okinawa, the aircraft struck the water surface, crashed and broke in three pieces that sank by a depth of 1,600 meters. Four crew members were found alive while eight others were killed.

Probable cause:

The exact cause of the accident could not be determined with certainty. However, it is believed the accident may have been caused by an accidental disconnection of the automatic pilot system.